In mechanical timepieces, in particular wristwatches with hands, time-setting devices are known that are actuated by a crown, kinematically connected to the motion work of the watch in the axial position thereof corresponding to the time-setting mode, with determined gear ratios for moving the minute hand simply and quickly without having to rotate the crown for too long or too often.
In electronic timepieces with a digital display, in particular a liquid crystal display, it is known to accelerate the scrolling speed of the digital symbols by the prolonged or repeated actuation of a sensor when the timepiece is in a specific adjustment or setting mode. For example, a prolonged application of pressure to the push button accelerates scrolling to a maximum velocity value for the display value to be corrected. The adjustment is then performed sequentially for each display setting.
It is also known to correct a digital display by using a crown provided with sensors as the actuation element, and an electronic control device for correction at a velocity proportional to the rotational velocity of the crown, such as for example, the electronic circuit disclosed in GB Patent No. 2019049. In this case, the correction speeds are constant between different plateaux corresponding to rotational speeds of the crown, but they may however change suddenly upon each incrementation. Moreover, no correction occurs between two successive movements of the crown, and no mechanism is provided for slowing down the scrolling of the counter used for correction. Thus, a fine adjustment requires repeated low amplitude activations by the user, to generate the lowest possible correction velocity. On the one hand this is inconvenient, and on the other hand it does not overcome the jerky movement of the hands.
CH Patent No. 641630 discloses an electronic device for scrolling through symbols at a variable velocity in response to the actuation of a sensor (by moving a finger on a tactile sensor, pressure on a push button). The number of actuations of the sensors and the duration of these actuations have the effect of incrementing or decrementing the values contained in a register, which in turn determine a proportional scrolling velocity. Decrementing the values in the register after prolonged inactivation of the sensors gradually decreases the scrolling speed. However, this slowing down of the scrolling speed still lacks smoothness since the relative variations in the scrolling velocity increase as the register values come closer to zero. This solution has the advantage of using sensors without any mechanical parts. The drawback is that they are less intuitive to use than a conventional crown. Moreover, this solution only concerns digital displays and does not apply to watches with analogue display members.
It is also known, particularly in electromechanical watches, to display the direction of magnetic north by means of hands. However, the movement of the hand indicating north is often jerky and consequently not intuitive for the watch user.